1. Field of the Invention
The present invention relates to a hydraulically damping rubber or elastic bearing including an inner part, and an outer part oriented concentrically or eccentrically in relation to the inner part, and at some distance from the inner part. The bearing can also include a rubber or elastic part inserted between the inner part and the outer part, in which rubber part there are at least two chambers filled with damping medium, whereby the chambers are connected to one another by means of a flow connection.
2. Background Information
German Laid Open Patent Application No. 38 27 905, which corresponds to U.S. Pat. No. 4,953,833 to Schmidt et al. (Sep. 4, 1990), for example, discloses a hydraulically damping rubber bearing such as that described above, in which a rubber element is located between the outer part and the inner part, whereby the chambers filled with damping medium are connected to one another by means of a flow connection. The flow connection thereby runs in the form of a passage in the outer tube, or in the end-window tube of the rubber part, which means that an additional lathe turning or deformation operation is typically necessary to manufacture the flow connection. The cross section of such a passage also tends to be subject to corresponding manufacturing tolerances, so that variations of the damping values will almost inevitably occur in the context of series production.
Also disclosed are hydraulically damping rubber bearings in which the flow connection is located directly in the rubber part, whereby the cross section of the damping passage not only tends to be imprecise, but also cannot typically be manufactured with a sufficiently small diameter. The tolerances also tend to be subject to a rather large spread during manufacture. Further, there is also a risk that changes in the cross section of the passage can occur during the operation of the rubber bearing, as a result of corresponding deformations of the rubber part.